The major goals of this project are: 1) to prospectively examine risk factors for Alzheimer's Disease (AD) previoulsy identified in case control studies, including head trauma, thyroid disease, maternal age, cataracts, and family history of hematological malignancy; 2) to identify potential new risk factors and associated conditions of Alzheimer's Disease which may play a role in the development of the disease, such as smoking, lipid and lipoprotein profiles, cardiac status, glucose tolerance, and environmental or social factors; and 3) to determine if age-associated declines in psychological or physiological functions are precursors of the eventual development of dementia. Core B - Clinical Studies. The major goals of this core are: 1) to recruit new AD patients and controls for longitudinal neuropsychological, neuroimaging and clinicopathological studies; 2) to continue longitudinal studies of end-stage dementia in surviving members of the original ADRC cohort; and 3) to investigate clinicopathological correlates of normal aging in BLSA subjects who have consented to autopsy.